If the Sun was Frozen
by ThereWasColdLikeDeath
Summary: After an expedition gone wrong leaves the Survey Corps crippled from losses and forces Eren Jaeger to change into his titan form, the Military Police is given custody of Eren for a full month for the purpose of experimentation before his fate is decided. What his comrades don't know, is what exactly happened to him behind closed doors. (Based off the anime, not the manga!)
1. Prologue

**This is my first fanfiction, so I hope you enjoy! This takes place in the canon universe, after the deal with the female Titan and the death of Levi's squad.**

 **I haven't read the manga, I have only seen the anime, so please forgive any mistakes I make or assumptions I make about the plot or characters! Enjoy!**

* * *

As soon as the first wave of Titans hit, Levi knew they had fucked up.

There were countless reasons as to why this plan had been a bad idea: too soon after the last expedition, the new recruits were still rattled, heavy losses meant a change in formation that was not going to work for anyone. It wasn't that he didn't trust Erwin's judgement; on the contrary, the man had such a talent for quick perception and tactic that Levi grudgingly trusted his word over most. This had been a situation that had been imposed upon them by external forces, and against Erwin's wishes, the Survey Corps was in no position to disobey. Levi did not know the details, and frankly he could not care less; what was weighing more heavily on his mind was how many of his subordinates he knew were going to die today. Distant screams were drawing closer, and even from his position towards the center of the formation, he could feel the ground tremble from colossal footsteps and saw the signal flares tainting the sky all around him in an explosion of toxic color.

Casting a glance over his shoulder, Levi's eyes locked on their target: Eren Jaeger. Some of the more seasoned members of the Corps were in a loose circle around him, their faces calm but their eyes barely containing the waves of fear ready to burst from their delicate, shaking bodies. It was an expression that Levi was not unfamiliar with. After the time he spent outside the walls, and even in the times long before, Levi had come to know the true frailty of the human form, and as their comrades were plucked away, one by one, he knew they realized it too. However, this was not what he was concerned with, he would allow the terror in those eyes to return to him later, as they always did without fail. His priority was the intentions of the titan boy.

The words from their last encounter on an expedition were suddenly ringing in his ears. _The best you can do is to make your choice with no regrets._ Undesired memories flickered past his vision, but where quickly repressed. He had been at the mercy of the boy's whims before, and once again he was left to act based on whatever the brat had planned in his thick skull. Would he make the same choice as before, and rely on Levi? Or would he react to the sudden slaughter of his fellow soldiers with that heated passion that seemed to be constantly broiling just beneath the surface?

Eren's gaze shifted from the calamity that was quickly closing in on them and connected, with a flash of surprise, to the cold stare of his captain. They both knew, without saying it out loud, that the death of his squad members had changed Eren. Something dark suddenly swept over the boy's youthful green irises, and a cold shock briefly seized hold of Levi's heart before he settled into grim resignation. Turning forward, his eyes fixated on the fluttering image of the Wings of Freedom on the sea of cloaks that spread out before him as he felt heat, then an explosion of hot air and blinding light that preluded to an inhuman roar that seemed to freeze time.

* * *

"No."

The answer was curt, and to the point; not that anything less had been expected from Captain Levi. He was leaned against Erwin's desk, his arms crossed over his chest and his face fixed into a bored frown, though the naturally worn lilt of his voice had taken on an annoyed tone that forced Erwin to cut in with a tight, diplomatic smile. The soldier, his uniform and arrogant posture, though slightly less aloof beneath the burning glare of Levi, clearly stating his position in the Military Police, was here on dangerous business and they were in a rather difficult situation that did not require more agitation from the short captain's harsh manners.

"I'm sure this can be worked out. At Cadet Jaeger's trial, the circumstances of his time with us were outlined to meet the needs of all those involved." The man scoffed, attempting to hide his discomfort beneath an awkward yet cocky alteration in the arrangement of his arms.

"That monster has no reason to still be alive, and though you may have fooled Zackly, we knew you couldn't handle it. And now you've proved us right. The Military Police has been granted full custody of Eren Jaeger, and if in a month we have discovered more about it's Titan-shifting abilities than you have managed to, that thing will never walk among the ranks of humanity again." The soldier's smirk faltered slightly when Levi lifted his face from staring blankly at the wall, seemingly tuned out of the conversation.

"So you pigs decided to stop rolling around in your own shit long enough to realize the world is bigger than your disgusting pigsty? Beyond the walls, even with the best tactical plan humanity could pull together, there is no way that every possible scenario may be accounted for. So maybe after you pull your head out of your ass long enough to think without feeling constipated, we can talk about the best action to take with Jaeger." After years of practice, Erwin found himself able to keep his expression entirely neutral, however the blood had completely drained from the soldier's face and his jaw hung open like a fish gasping for air. Finally, after a few minutes of collecting himself, the man pulled a document from his jacket, stalked over, and slammed it on Erwin's desk before retreating to a safer distance from Levi's steel eyes.

"That is an official letter confirming the change in custody to the Military Police. There is nothing you can do to get out of this. My men should be extracting and transporting the abomination as we speak. If you have a problem with this, you can take it to the higher-ups, but for now I am following my orders and you cannot stop me." Levi took a step forward, his arms swinging down to rest casually by his sides.

"Levi," Erwin stopped the captain's advance with a low warning. Not even bothering to salute, the soldier scurried from the office and slammed the door shut behind him. Turning slowly, Levi met Erwin's calm gaze with an unimpressed stare.

"I hope you know what you're doing." Sighing, Erwin rested his elbows on his desk and pressed his fingertips lightly into his temples.

"So do I."


	2. Chapter 1

**Here comes Chapter 1!**

 **TRIGGER WARNING: There is possible violence that may disturb some readers, and mentions of torture and needles.**

 **Enjoy!**

* * *

"Wake up."

"Wake up!"

Cold water splashing over bare skin jolted Eren awake. He looked around in shock, struggling to gain his bearings, to find himself in a dark room. There were no windows, only tall candles and faint light peeking from beneath a sturdy wooden door; the walls were brick and had been painted a very light shade of brown, which helped reduce the depths of the shadows. Standing before him was a young man in Military Police uniform, holding an empty bucket and smiling apologetically. He had very short blond hair, big tawny eyes and fidgeting hands, Eren noted; he didn't seem able to just hold the bucket, his fingers were almost uncontrollably twitching.

"Thank you, Jonathan." A voice came from nowhere, and Jonathan shyly retreated to stand behind an older man that Eren had not yet noticed. His eyes were small and hard, void of emotion, and his mouth was a tight line set into a face covered in wrinkles and a retreating hairline. He clearly had been in the military for many years, and a part of Eren was bitter that he probably only reached such an age during this war because he could stay safe behind the walls.

"What's going on? Where am I?" After attempting to move, he looked down and realized he was strapped to a hard wooden chair by thick metal cuffs on his wrists and ankles, leaving him completely immobilized and defenseless. Eyes widening in realization, Eren felt a twinge of fear in his chest that quickly spread like poison to the rest of his body when the man stepped closer.

"Don't bother trying to escape from those. Unless you manage to figure out a way to hurt yourself and shift, you are at my mercy- so I suggest you show me some manners when we get going."

"Get going?" Confusion swirled into the mix of emotion raging in Eren's mind. The man ignored the question and gestured to Jonathan, who scurried about and brought over a tray of plain food, managing to silently convince Eren to open his mouth and let himself be fed. While this happened, the man began speaking again.

"You should eat to gather your strength, it's going to be a long day today. First things first, my name is Evron Viteri, and I am an officer in the Military Police. I will be the one leading the investigation during your time here, and this is my new assistant, Jonathan Tracey, who will be taking care of all of your basic needs. Think of him as an extension of me, so don't try to treat him poorly or coax him into doing anything. He may be young, but he is not gullible and he knows his place. Soon, you will learn yours." As he finished the curt introductions, Eren had all but cleaned the plate of food, nodding a silent _thank you_ to Jonathan, who only smiled back before taking away the tray and setting it on a long table in the far corner of the small room, which was covered in random objects that Eren did not recognize.

"Before we can truly begin, I have to ask you some questions that you must answer completely truthfully and to the best of your ability." Eren nodded hesitantly, because as much as he would have liked to get angry and fight, he knew he was trapped and would only make it worse; his sole consolation was the knowledge that if he had to, he was capable of breaking himself free. He was impulsive but he was not a fool, he had the Survey Corps and Armin and Mikasa to live for; he refused to let himself be cut down by weaklings in the Military Police. He recalled what Levi had said to him before he was taken: _don't mess up and give them a reason to kill you, brat._ Under the weight of his promise, a surge of determination filled him with confidence.

To his surprise, Viteri's questions were basic ones: _where were you born, how old are you, what is your father's name,_ simple questions about his origins and his life. Eren answered each one with unwavering eye contact, his fear slowly subsiding as nothing abnormal happened. _Is this all? What exactly do they have planned?_ He had little time to ponder what was coming when Viteri suddenly stood from the stool he had been resting on.

"Very good. Now, to the important part. If we are to be successful at anything we try with you, there are certain precautions we must take. I hope you're not afraid of needles." The statement was made clear when Jonathan handed Viteri a large syringe filled with a murky liquid. Deja vu filled Eren with dread, and he strained against the cuffs as Viteri came closer. A calloused, strong hand shot out and gripped Eren's arm.

"Stay still, boy. This will make it a lot easier for all of us..." The thin metal pierced his skin, and Eren sank his teeth into his tongue to keep any noises from emerging as, soon after, the room started to slide in and out of focus and his thoughts became clouded and jumbled.

"Don't fight it, boy. Let yourself sink into whatever you are feeling."

Everything went black.

* * *

More cold water. Eren gasped, his head snapping up before quickly sagging back down. He felt dizzy, incredibly thirsty, and his eyes still felt slightly clouded over, like he was losing his vision. The world was bright, and he could feel a headache coming just from trying to adjust to it. A breeze kissed his cheek, and with a flare of hope he realized he was outside. Forcing his eyes to comprehend his surroundings, he looked around and saw grass, and five figures standing around him. Jonathan was again holding an empty bucket, wearing a sheepish smile that Eren quickly recognized to be an expression of the boy's awkwardness and friendly attitude. Behind him was Viteri, and closing them in were three Military Police soldiers, weapons ready; he figured there were probably more that he could not see. When he reached up to rub his eyes in an effort to improve his sight, he saw that his hands were cuffed together, like at his trial, but this time they weren't behind him; which meant if he needed to, he could bite his thumb and be free.

"I know what you're thinking," Viteri's voice rang out over the open field they were apparently in the middle of, causing Eren to look up in surprise. "Go ahead, do it. Bite your thumb. Turn into a titan." Jonathan nodded and smiled with encouragement, before retreating to his captain's side. Hesitating, he looked down at his hands. _They asked me to do it, so it's not like I'm breaking the rules. They clearing want something from this, I just can't figure out what it is!_ Huffing in frustration, Eren lightly sucked in his bottom lip before bracing himself and biting down into his thumb, hard. His mouth filled with bitter iron and he winced as he felt his hand twinge with pain, waiting for the change to come. Nothing happened. Recalling the first time he tried to change in Hange's well and their discovery with the teaspoon, Eren scrambled his brain for something to focus on that would allow him to change. _I can't disappoint Levi._ The thought passed through his fogged mind, and he grasped it; better than nothing. He bit into his skin again, and again, and again, but nothing happened. He stared at his bloodied hands in shock and looked up at Viteri, who had strode over and was now hovering over Eren with a mysterious glint in his eyes.

"Just as we suspected. The serum worked. As long as we keep that pumping in your system, we can keep you out of titan form for as long as we want."

"W-what do you mean?!"

Sharp pain exploded in the back of his head, and the world went dark again.

* * *

This time, the soft murmur of voices brought Eren back in consciousness. By the table on the other side of the room, Jonathan and Viteri were in quiet consultation with each other and hadn't noticed their prisoner was awake. A low groan left his lips by mistake when he suddenly felt his head throbbing, and they both quickly turned to face him. Jonathan hurried over with a glass of water, and Eren gulped it down eagerly, attempting to convey his gratitude to Jonathan with a kind expression.

"Ah, you're back with us. Tell me, how long does it usually take you to heal?" The question took him aback.

"U-uh, it depends on the wound, sir. But I heal faster-"

"Yes, yes, I know. We've all heard of your miraculous healing ability. How long would it take you, normally, to heal from a shallow cut on your arm?" Unsure of whether to answer truthfully, but unable to think of anything else because of his scattered thoughts, Eren licked his lips and responded.

"A few minutes, maybe a bit longer- OW!" He looked down in disbelief. In a matter of moments, Viteri had crossed the room and swiftly dragged a thin, sharp knife over his forearm. Dark red blood pooled and spilled out of his skin, dripping onto the chair and the floor.

"Jonathan, are you getting this?"

"Yes, sir." Eren whipped his head around to see the shy boy holding a small hourglass between his hands, watching the trickle of sand closely. When their eyes met, Jonathan blushed and looked away. When five minutes had passed, the cut had still not healed. They waited, and after half an hour, there was no sign of steam or any indication of his normal healing process other than the fact that the bleeding had stopped.

"Interesting. It looks like even your titan healing abilities have been repressed." Eren couldn't stop staring at the cut on his arm. _What does this mean?_

In the next few hours, he quickly discovered exactly what that meant.

It was the same schedule, every day. In the morning, Jonathan would come in, feed him, tend his wounds, let Eren relieve himself. Then Viteri would show up soon after and the day would properly begin. It started with simple observations of his external healing, testing different depths and types of flesh wounds, and most of the time Eren was able to force himself to stay silent throughout. Other than handing Viteri different tools, Jonathan stayed back and only cleaned up the blood. Sometimes, when his captain left, Jonathan would linger and they would chatter with what energy Eren had left; he was certain it was these brief conversations that helped him stay sane in the beginning. However, after a while Eren started to notice changes in routine; Viteri started showing up later and finishing earlier, when Eren screamed too loud he would have Jonathan gag him, and sometimes he would order the boy to use stitches or special bandages when it got really bad. Then, one day, Viteri never showed up.

"W-where is he?" Eren asked, his words slurred from the effects of the serum that had been administered to him only minutes before, and voice laced with exhaustion. Jonathan had been buzzing about the small room, doing different things that the restrained boy hardly had the energy to focus on. A small smile of affection tugged at his lips as he watched his torturer's assistant; the young man had truly treated him with kindness, and perhaps if they hadn't met under these circumstances they could have been friends. To a certain extent, he even trusted the one who woke him gently in the morning to a plate of food and a glass of cool water, and at night sent him to sleep with a friendly farewell. They had formed a unique bond that made Eren feel slightly less hopeless in his days filled with intolerable pain.

Upon hearing the question, Jonathan turned to face Eren with his usual smile, but there was something slightly different about his expression that he couldn't quite place.

"Oh, Captain Evron isn't coming in today. It's just you and me."


End file.
